Rowling's Dr Who cameo scrapped for Tennant

The famed novelist was due to appear in a special Christmas episode of the sci-fi series, but Tennant is said to have disapproved of the plans.

And TV bosses were determined to keep the star on side.

In a series of recently published emails, Doctor Who writer Russell T. Davies wrote, "David doesn't like the JK idea. He thinks it sounds like a spoof, so we've paused slightly, wondering whether to win him round or just abandon something that's not going to make him happy. We've got to keep him happy, because he keeps us happy."